That's a useful suggestion, but my question concerned how to calculate the ADD value, rather than determining it empirically.
On Oct 20, 6:16 am, Chuck Knight <[email protected]> wrote: > Go to your local store, probably WalMart or similar, and be sure to wear > your regular glasses. Then, while wearing your regular glasses, try on the > standard readers by placing them in front of your regular ones. > > The value of the reader that works best for you at the desired distance is > the ADD value you need. > > -- Chuck Knight > > > > > > > > On Sat, Oct 16, 2010 at 7:04 PM, Greg <[email protected]> wrote: > > How do you calculate what sphere additional value to specify if you > > want your monovision glasses to work best at x distance --- e.g., at > > 28" from a computer screen? I've ordered three pairs of glasses to > > use with my computer, and for the last two, I added 0.75 to the SPH > > values of my prescription (which worked well), then 1.00 (which worked > > a little better). It's just been guess work, so far, since I've never > > seen a formula that would give an analytic approximation. At my last > > eye exam, I asked my optometrist what values I should use for my > > computer screen, and she told me to add 1.50 assuming my computer > > screen was 22" away. Maybe that was right, but how do I know? (Just > > going on intuition, I decided 1.50 was too high, and I ordered some > > glasses from Zinni using an add value of 1.00, and those seem to be > > okay.) > > > --Greg > > > -- > > Check us out at the oft-updatedhttp://glassyeyes.blogspot.com! > > > You received this message because you are subscribed to the Google Groups > > "GlassyEyes" group. > > To post to this group, send email to [email protected] > > To unsubscribe from this group, send email to > > [email protected] > > For more options, visit this group at > >http://groups.google.com/group/glassyeyes?hl=en -- Check us out at the oft-updated http://glassyeyes.blogspot.com! You received this message because you are subscribed to the Google Groups "GlassyEyes" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/glassyeyes?hl=en
